
import java.util.Scanner;

class PRIMO {

    static Scanner entrada = new Scanner(System.in);

    public static void main(String[] args) {

        int N = entrada.nextInt();

        int cont = 0;

        for (int i = 1; i <= N; i++) {
            if (N % i == 0) {
                cont++;
            }
        }
        if (cont == 2) {
            System.out.println("sim");
        } else {
            System.out.println("nao");
        }
    }
}
